Noun

(en noun)

A certificate that certifies an amount of money owed to someone; a certificate of indebtedness.

(obsolete) A certificate of a loan made to the government; a government bond.

* 1942 , Elliot Paul, The Last Time I Saw Paris , Sickle Moon 2001, p. 72:

Madame Corre, who made the important decisions after her plodding husband had spent hours on the ledger, sold the family debentures and put the money into Dutch decurities.

(finance) A type of bond secured only by the general credit or promise to pay of the issuer, now commonly issued by large, well established corporations with adequate credit ratings.

*

, title=The Mirror and the Lamp , chapter=2 citation , passage=That the young Mr. Churchills liked—but they did not like him coming round of an evening and drinking weak whisky-and-water while he held forth on railway debentures and corporation loans. Mr. Barrett, however, by fawning and flattery, seemed to be able to make not only Mrs. Churchill but everyone else do what he desired.}}

Noun

(en noun)

Something derived.

(linguistics) A word that derives from another one.

(finance) A financial instrument whose value depends on the valuation of an underlying asset; such as a warrant, an option etc.

(chemistry) A chemical derived from another.

(calculus) The derived function of a function.

The derivative of $f:f(x)\; =\; x^2$ is $f\text{'}:f\text{'}(x)\; =\; 2x$

(calculus) The value of this function for a given value of its independent variable.

The derivative of $f(x)\; =\; x^2$ at x = 3 is $f\text{'}(3)\; =\; 2\; *\; 3\; =\; 6$.